PB2044: TRIAL IN PROGRESS: OBSERVATIONAL STUDY IN PATIENTS WITH ADVANCED SYSTEMIC MASTOCYTOSIS TREATED IN ITALY WITH MIDOSTAURIN (OVIDIO)
Authors: F. I. Grifoni, F. Mannelli, C. Papayannidis, M. Triggiani, R. Bini, D. Valsecchi, R. Zanotti
Journal: HemaSphere (2022)

Background: Mastocytosis is a group of diseases resulting from the accumulation of clonal mast cells (MC) in one or more organ systems. The World Health Organization (WHO) classifies the disease into cutaneous mastocytosis (CM), systemic mastocytosis (SM), and localized mast cell tumors. SM is further divided into indolent/smoldering SM and advanced SM (AdvSM), that includes aggressive SM (ASM), SM with associated hematological neoplasm (SM-AHN) and mast cell leukemia (MCL) (Valent 2022). Treatment with midostaurin, the first orally multikinase/KIT inhibitor approved for AdvSM in both the United States and the European Union in 2017, resulted in a relevant clinical activity with an acceptable safety profile as demonstrated by two single-arm trials (Gotlib 2016, DeAngelo 2018). After approval, few real-world evidence (RWE) reports have been published on the safety and efficacy of midostaurin. Indeed, sound evidence from a large real-world setting confirming the impact of midostaurin on disease burden, efficacy parameters, quality of life and safety is lacking. Also, reports on efficacy data according the International Working Group–Myeloproliferative Neoplasms Research and Treatment–European Competence Network on Mastocytosis (IWG-MRT-ECNM) response criteria are limited (Tzogani 2019, Szudy-Szczyrek 2021). Aims: The non-interventional OVIDIO study aims to describe a cohort of patients with AdvSM treated with midostaurin according to local label and a cohort of patients with AdvSM non treated with midostaurin in clinical practice, to fill the knowledge gap between the clinical experience from registration trials and routine patient’s management in Italy. Methods: OVIDIO is a multicenter, non-randomized, observational study in adult male and female patients with AdvSM. The study includes two cohorts: 1) patients with AdvSM treated with midostaurin starting from Jan 2016. The data collection period is of 60 months from the start of midostaurin treatment; 2) patients with AdvSM not treated with midostaurin (diagnosis between Jan 2010 - Dec 2015). The data collection period is of 60 months from the initial diagnosis of AdvSM. Patients’ data will be entered in the clinical database after all necessary local approvals from Ethics Committees and following the patient’s signed informed consent, if applicable. The study is conducted at approximately 25 sites located in Italy and it will enroll up to 80 patients in the midostaurin-treated cohort and up to 50 patients in the midostaurin-not treated cohort. The study co-primary objectives are: i) to describe the profile and disease burden of a cohort of patients with AdvSM treated with midostaurin according to approved local label; ii) to describe the profile and disease burden of a cohort of patients with AdvSM not treated with midostaurin. Secondary objectives include the characterization of clinical management in both cohorts and, specifically for midostaurin cohort, the evaluation of the effectiveness according to IWG-MRT-ECNM criteria, the impact on the quality of life (QoL) and the safety of midostaurin in AdvSM. As exploratory objective, the study will also compare the overall survival (OS) between patients treated and not treated with midostaurin. Results: Trial in Progress. First interim data will be made available by the end of 2022. Summary/Conclusion: As of February 2022, 64 and 18 patients have been enrolled in the midostaurin treated and not treated cohort respectively. Enrollment is ongoing.